In general, a fuel cell system receives electric power from a system power supply to which the fuel cell system is interconnected to, and drives a control device and accessory devices to heat up intended portions of the system by means of, for example, a combustor and an electric heater, thereby starting up and performing electric power generation by a fuel cell. In order to avoid a situation where the fuel cell system is unable to start up due to a power outage in which the power supply from the system power supply is stopped, an emergency-responsive fuel cell system disclosed in, for example, Patent Literature 1 includes a power generator and uses electric power from the power generator for the start-up when a power outage has occurred.
Moreover, in order to reduce electric power consumption at start-up, for example, a fuel cell system disclosed in Patent Literature 2 includes a burner and an electric heater, and when a power outage has occurred, the fuel cell system operates the burner without operating the electric heater. Accordingly, a hydrogen generator is heated solely by the burner, and electric power consumption by the electric heater is reduced.